Great Britain's Laura Trott repeats as gold medalist in the women's track omnium, and American Sarah Hammer earns another silver in Rio.
The American track program was revamped for the Rio Games, with the team pursuit squad winning the 2015 world title.
A young American team of Sarah Hammer, Jennifer Valente, Chloe Dygert, and Kelly Catlin breaks U.S. team pursuit record at worlds.
The 31-year-old wins the first ever U.S. World Cup medal in the men's omnium
American Sarah Hammer took a second consecutive omnium title at the world track championships
Hammer wins second title of 2013 track worlds on the event's closing day
American rides to within one world title of the all-time IP record
American is one win behind compatriot Rebecca Twigg and Russian Tamara Garkuchina for the IP record
Hammer narrowly misses out on track gold
Trott, Hammer locked in tight race for the first women's Olympic omnium title